Adding machine



March 24, 1942. l T. o. MEHAN ADDING MACHINE Filed June 17, 1937 NSN,

Patented Mar. 24, 1942 UNITED STATES PATENT OFFICE t 2,277,498 i ADDING MACHINE Thomas 0. Mehan, Chicago, Ill., assignor to Victor Adding Machine Company. Chicago, Ill., a corporation of Illinois I f Application June 17, 1937, sensi' Ns. 148.641

4 claims. (c1. 2x5-so) My invention relates generally to adding ma` chines, and more particularly to improvements in accumulator actuating mechanisms.

lIt is an object of my invention to provide an improved mechanism for driving the ac cumulator pinions lof adding machines,` cash registers. and the like, which-is simple in construction and may be economically manufactured.

A further object is to provide animproved resilient drive for the actuation of the accumulator pinions, in which a single spring performs the function of actuating the accumulator during the transfer or carry-over operation as well as during the amount entering operation.

Afurther object is to provide an improved accumulator actuating mechanism having few` parts, which`may be readily manufactured and assembled.

Other objects will appear from the following description, reference being had tothe accompanying drawing, in which:

Figure 1' is a longitudinal sectional view of the adding machine, showing the set-up and actuating mechanisms:

Figure 2 is an enlarged transverse sectional view taken on the line ,2--2 of Figure l;

Figure 3 is a fragmentary sectional view `taken on the line 3 3 of Figure2; and

Figure 4 is an enlarged sectional view of the on the line 4-4 of Figure 1.

In my copending application Serial No. 123,320, filed February 1, 193'?, is disclosed an improved ten-key adding machine of the type to which my present invention pertains. Inasmuch as the present invention is concerned only with the accumulator actuating mechanism, only such parts which cooperate directly with this mechanism will be described herein. Y' The amounts to be added are set up by means of the usual keyboard having ten depressible, spring-returned digit keys I8, each having Va depending stem I2.. The stems I2 are in alignment and their lower ends normally lie above a row oi stop pins I4/which are mounted in the usual manner in a stop pin carriageA I8.

by a pair ofrails I8, 28.

A plurality of actuating racks 22, one for each denominational order of the machine, and each having a stop shoulder, are guided for longitudinal movement by rods 24, 28,` and 28, the

latter rod projectingvthrough a slot 38 formed actuating gear (with its spring removed) taken pawl may falso be tripped by the transfer tooth The 1 latter is transversely reciprocable, being carried in properly spaced 32, 34.

Each of the racks 22 meshes with an accumulator and typewheel actuating gear 38, mounted relation by a pair of combs for free rotation upon a iixed shaft38. An idler pinion 48 is arranged to be me'shed with the*l which is vertically slidable upon apair of swinging levers 51.

The accumulator actuating gear 38 is provided `with an arcuate slot 58 toreceive a bailv rody 8|! carried by bail arms 82, the latter being nonrotatably secured to shaft 38. Each of the gears 38 is staked to a hub 84 having a flange' 88. ,A

torsion spring 88 is wound about thehub 84 be- I tween the gear 38 and the flange 88, and has its, ends 18, 'I2 held apart by a suitably notchedlug -14 struck inwardly from the gear 38.

coil of the spring nearest the end 18 'is bent to form a loop 18 .which fits around a pin 18 riveted `in the gear 38 and is thereby anchored to the gear. The end 18 will therefore be slightly less elastic than the end 12.

The transfer or carry-over is effected by the engagement of the usual transfer tooth (extendingsidewardly from one of the teeth of the accumulator pinion 48) with the cam projection 18 of a transfer pawl'88. When a transfer is to be effected, the pawl 88 is swung clockwise to remove the stop portion'82 thereof from arresting position above the lug 84 which projects sidewardly from the gear 38 of next adjacent higher denominational order. After one of the pawls 88 has been tripped, it is held in tripped position by a spring operated latch 88. The transfer on its associated subtraction wheel 48.

In. operation, the amount to be added is set up in the p in carriage I8 in the usual manner by successive depression oil the'desiredkeys I8. j Upon initiation of the operating cycle of th'e,

machine, the bail 88, 82 will commence swinging counter-clockwise and, after it has moved through about 15 from the position in which it in each of the racks. The racks are maintained 88 is shown in Fig. 3, the bail'rod 88 will engage The the end 'I2 of the spring 68 and through the spring 68 resiliently drive the gear 3B counterclockwise. 'I'he rack 22 will thus be drawn rearwardly (to the right in Fig. l) until its stop tooth 23 abuts against a stop pin I4 which may have been set. After the rack is thus arrested by a stop pin, continued movement of the bail rod 80 is permitted by the exure of the end 12 of the spring 68. During this portion of the operation, the accumulator pinions will have been held out of mesh, but the idler pinions will have been in mesh with the actuating gear 38, and the type wheels 42 thus properly positioned.

After the type wheels have been actuated to make a printing impression, their idler pinions 40 are again meshed with the gears 38 and at about the same time the accumulator pinions 48 (or subtraction pinions 48) are meshed with the gears 36. The bail`60, 62 then commences itsclockwise (return) stroke, and upon engagement of the bail rod 60 with the ends 10 of the springs 68, the gears 36 are successively picked up and restored to normal position, as determined by the abutment of their lugs 84 with the stop portions 82 of the transfer pawls 80. However, if any transfer pawls 80 have been tripped, the gears 38 associated therewith will be permitted to move the additional angular distance represented by one tooth, because their lugs 84 will not be arrested until they strike the pawls 80 within the notches formed adjacent their stop portions 82. The bail rod 88 swings through a sulciently great angle" to provide for this additional transfer movement of the gears 36. The flexure of the end I8 of the spring 88 permits such additional movement of the bail rod 60 relative to ythe gears 36 which are not to e'ect a transfer operation.

From the above description it will be apparent that the springs 68 not only form the resilient means to actuate the racks, accumulator pinions and type wheelsv during the forward and return strokes of the latter, but also serve as the resilient means to move these parts in effecting a transfer operation. The spring 68, being mounted in the relatively enclosed space between the gear and the flange of its hub, is substantially a part of the gear, thus facilitating assembly, and forming a construction which is less costly to manufacture and more reliable in operation than the relatively long coiled tension springs customarily employed to actuate the racks in similar machines.

While I have shown and described a particular embodiment of my invention, it will be readily understood by those skilled in the art that variations may be made in the construction disclosed without departing from the basic features of my invention. I therefore do not wish to be limited to the precise construction disclosed, but wish to include within the scope of my invention all such modifications and variations which will readily suggest themselves.

What I claim as new and desire to secure by` Letters Patent of the United States is:

1. In an adding machine, the combination of an accumulator, an amount set-up mechanism, and means to actuate said accumulator in accordance with the amount set up in said mechanism, said means comprising an actuating gear having a hub, a torsion spring surrounding said hub and having a part thereof anchored to said gear, and a member movable to and fro through a xed distance and engageable with said spring to actuate said gear in either direction by a force transmitted through said spring.

2. In an' adding machine, the combination of an accumulator, an amount set-up mechanism. and means to actuate said accumulator in accordance with the amount set up in said mechanism, said means comprising an actuating gear,

a torsion spring having an intermediate part` thereof anchored to said gear, and a member movable to and fro through a fixed distance for actuating said gear, said member engaging one end of said spring to rotate said gear in one direction and engaging the other end of said spring to rotate said gear in the opposite direction.

3. In an adding machine, the combination of an accumulator, an amount set-up mechanism, and means to actuate said accumulator in accordance with the amount set up in said mechanism, said means comprising an actuating gear having an arcuate slot formed therein, a torsion spring substantially coaxial with said gear, having an intermediate portion anchored to said gear, and having its end portions projecting outwardly across said arcuate slot, a bail rod extending through said slot between the ends of said spring, and means to oscillate said bail rod through a definite angular distance about the axis of said gear, thereby to oscillate said gear through an angle determined by the amount set up in saidr mechanism by a force transmitted to said gear solely. through said spring.

4. An actuating mechanism for addingv machines, and the like, comprising a gear having a hub, a4 torsion spring wound around said hub and having a portion intermediate its ends anchored to said gear, and a lug on said gear forming a positive stop for the ends of said spring to hold said spring under tension.

THOMAS O. MEI-IAN. 

